Diagnostic device, system and method for reduced data transmission

ABSTRACT

A device, system and method may enable the obtaining of in vivo images from within body lumens or cavities, such as images the gastrointestinal (GI) tract, where the data such as image data is typically transmitted or otherwise sent to a receiving system in compressed or diluted form. The image may be reconstructed and for example displayed to a user.

PRIOR APPLICATIONS DATA

This application is a continuation of U.S. patent application Ser. No.10/551,436, entitled “DIAGNOSTIC DEVICE, SYSTEM AND METHOD FOR REDUCEDDATA TRANSMISSION”, filed Jul. 17, 2006, published on Nov. 23, 2006 asUnited States Patent Application Publication No. 2006/0262186, which ishereby incorporated by reference in its entirety, and which is aNational Phase Application of International Application No.PCT/IL2004/000287, entitled “DIAGNOSTIC DEVICE, SYSTEM AND METHOD FORREDUCED DATA TRANSMISSION”, filed Mar. 29, 2004, published on Oct. 14,2004 as International Application Publication No. WO 2004/088448, whichis hereby incorporated by reference in its entirety, and claims priorityand benefit from Israeli Patent Application Number 155175, entitled“DIAGNOSTIC DEVICE, SYSTEM AND METHOD FOR REDUCED DATA TRANSMISSION”,filed on Mar. 31, 2003, which is hereby incorporated by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates to an in vivo device, system and methodsuch as for imaging the digestive tract; more specifically, to an invivo device, system and method where information transmitted or sent, iscompressed.

BACKGROUND OF THE INVENTION

Devices and methods for performing in-vivo imaging of passages orcavities within a body, and for gathering information other than or inaddition to image information (e.g., temperature information, pressureinformation), are known in the art. Such devices may include, interglia, various endoscopic imaging systems and devices for performingimaging in various internal body cavities.

An in-vivo imaging device may include, for example, an imaging systemfor obtaining images from inside a body cavity or lumen, such as the GItract. The imaging system may include, for example, an illuminationunit, such as a set of light emitting diodes (LEDs), or other suitablelight sources. The device may include an imaging sensor and an opticalsystem, which focuses the images onto the imaging sensor. A transmitterand antenna may be included for transmitting the images signals. Areceiver/recorder, for example worn by the patient, may record and storeimage and other data. The recorded data may then be downloaded from thereceiver/recorder to a computer or workstation for display and analysis.Such imaging and other devices may transmit data such as image data orother data during a certain period of time. It may be desirable to limitthe amount of time spent transmitting image data, and also the bandwidthrequired for such a transmission. The time spent transmitting limits theamount of image or other data that may be transmitted. Other in-vivodiagnostic units need not transmit by radio waves, for example, image orother data collected may be sent via wire.

Therefore, there is a need for an in-vivo diagnostic device, such as animaging device, which more efficiently transmits data.

SUMMARY OF THE INVENTION

An embodiment of the device, system and method of the present inventionenables the obtaining of in vivo images from within body lumens orcavities, such as images of the gastrointestinal (GI) tract, where thedata such as image data is typically transmitted or otherwise sent to areceiving system. According to one embodiment of the invention, the datatransmitted, including, for example, image information, is compressed.The data may be reconstructed using suitable methods and, for example,displayed to a user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a schematic diagram of an in vivo imaging system accordingto one embodiment of the present invention;

FIG. 1B shows a schematic diagram of an in vivo imaging system accordingan embodiment of the present invention;

FIG. 1C shows a schematic diagram of an in vivo imaging system accordingan embodiment of the present invention;

FIG. 1D shows a schematic diagram of an in vivo imaging system accordingto an embodiment of the present invention;

FIG. 2 depicts a series of steps of a method according to an embodimentof the present invention;

FIG. 3 depicts a schematic diagram of a first exemplary dilution patternfor selecting pixels according to an embodiment of the presentinvention;

FIG. 4 depicts a schematic diagram of a second exemplary dilutionpattern for selecting pixels according to an embodiment of the presentinvention;

FIG. 5 depicts a schematic diagram of pixels of one color selectedaccording to an exemplary dilution pattern in accordance with thepresent invention;

FIG. 6 depicts a schematic diagram of partial reconstruction of an imagebased on pixels selected according to an exemplary dilution pattern inaccordance with the present invention; and

FIG. 7 depicts a series of steps of a method for reconstructing adiluted image according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In the following description, various aspects of the present inventionwill be described. For purposes of explanation, specific configurationsand details are set forth in order to provide a thorough understandingof the present invention. However, it will also be apparent to oneskilled in the art that the present invention may be practiced withoutthe specific details presented herein. Furthermore, well-known featuresmay be omitted or simplified in order not to obscure the presentinvention.

Embodiments of the system and method of the present invention may bepreferably used in conjunction with an imaging system or device such asdescribed in U.S. Pat. No. 5,604,531 to Iddan et al. and/or inapplication number WO 01/65995 entitled “A Device And System For In VivoImaging”, published on 13 Sep., 2001, both of which are herebyincorporated by reference. However, the device, system and methodaccording to the present invention may be used with any device providingimaging or other data from a body lumen or cavity. In alternateembodiments, the system and method of the present invention may be usedwith devices capturing information other than image information withinthe human body; for example, temperature, pressure or pH information,information on the location of the transmitting device, or otherinformation.

Reference is made to FIGS. 1A-1D, which show schematic diagrams of invivo imaging system according to embodiments of the present invention.In an exemplary embodiment shown in FIG. 1A, a device 40 may be aningestible capsule capturing images, but may be another sort of deviceand may collect information other than image information. Typically,device 40 may include at least one sensor such as an imager 46, forcapturing images, a processing chip or circuit 47 that processes thesignals generated by the imager 46, and one or more illumination sources42, for example one or more “white LEDs” or any other suitable lightsource, for illuminating the body lumen. An optical system 50,including, for example, one or more optical elements (not shown), suchas one or more lenses or composite lens assemblies (not shown), one ormore suitable optical filters (not shown), or any other suitable opticalelements (not shown), may aid in focusing reflected light onto theimager 46 and performing other light processing. Processing chip 47 neednot be a separate component; for example, processing or a processingchip may be integral to the imager 46. A non-image sensor 49, forexample, such as a temperature sensor, a pH sensor, or a pressure sensormay be included. In an alternate embodiment of the present inventionsensor 46 may be a non-image sensor such as a temperature sensor, a pHsensor, or a pressure sensor.

Device 40 typically includes a transmitter 41, for transmitting imageand possibly other information (e.g., control information, non-imagedata, etc.) to a receiving device, and a compression module 600, forcompressing data. The transmitter 41 may typically be an ultra low powerradio frequency (RF) transmitter with high bandwidth input, possiblyprovided in chip scale packaging. The transmitter may transmit via anantenna 48. The transmitter 41 may act as a controller may also includecircuitry and functionality for controlling the device 40. Typically,the device may include a power source 45, such as one or more batteries.For example, the power source 45 may include silver oxide batteries,lithium batteries, or other electrochemical cells having a high energydensity, or the like. Other suitable power sources may be used.

Other components and sets of components may be used. For example, thepower source may be an external power source transmitting power to thecapsule, for example as described in a patent application withInternational Publication Number WO 02/080753 A2, and a controllerseparate from the transmitter 41 may be used.

In one embodiment, the imager 46 may be a complementary metal oxidesemiconductor (CMOS) imaging camera. The CMOS imager may typically be anultra low power imager and may be provided in chip scale packaging(CSP). One suitable CMOS camera may be, for example, a “camera on achip” CMOS imager specified by Given Imaging Ltd. of Israel and designedby Photobit Corp. of California, USA, with integrated active pixel andpost processing circuitry. Other types of CMOS imagers may be used. Inanother embodiment, another imager may be used, such as a CCD imager, oranother imager.

Typically, the device 40 is swallowed by a patient and traverses apatient's GI tract, however, other body lumens or cavities, such asblood vessels, the female reproductive tract, etc., may be imaged orexamined. The device 40 transmits image and possibly other data tocomponents located outside the patient's body, which may receive andprocess the data. Preferably, located outside the patient's body in oneor more locations, may be a receiver 12, preferably including orattached to an antenna or antenna array 15, for receiving image andpossibly other data from device 40, and a controller or processor 113, areceiver storage unit 16, for storing image and other data, a dataprocessor 14, a data processor storage unit 19, a data decompressionmodule 610 for decompressing data, and an image monitor 18, fordisplaying, inter alia, the images or reconstructed versions of theimages transmitted by the device 40 and recorded by the receiver 12.Typically, the receiver 12 and receiver storage unit 16 may be small andportable, and may be worn on the patient's body during recording of theimages. Preferably, data processor 14, data processor storage unit 19and monitor 18 may be part of a personal computer or workstation, whichincludes, for example, standard components such as a processor 13, amemory (e.g., storage 19, or other memory), a disk drive, andinput-output devices, although alternate configurations are possible. Inalternate embodiments, the data reception and storage components may beof another suitable configuration. Further, image and other data may bereceived in other manners, by other sets of components. Typically, inoperation, image data may be transferred to the data processor 14,which, in conjunction with processor 13 and software, may store,possibly process, and display the image data on monitor 18. Othersystems and methods of storing and/or displaying collected image datamay be used. Any of data processor 14, processor 13, receiver 12,controller 113, or another component or set of components, may act as orinclude a suitable controller or processor for, inter alia, controllingthe receipt and transfer of data, reconstructing data, decompressingdata, etc.

Typically, the device 40 transmits image information in discreteportions. Each portion typically corresponds to an image or frame. Othertransmission methods are possible. For example, the device 40 maycapture an image once every half second, and, after capturing such animage, may transmit the image to the receiving antenna. Other capturerates may be possible. Typically, the image data recorded andtransmitted may be a digital color image data, although in alternateembodiments other image formats (e.g., black and white image data) maybe used. In one embodiment, each frame of image data includes 256 rowsof 256 pixels each, each pixel including data for color and brightness,according to known methods. For example, in each pixel, color may berepresented by a mosaic of four sub-pixels, each sub-pixel correspondingto primaries such as red, green, or blue (where one primary isrepresented twice). In other embodiments, each pixel may capture onlyone color. The brightness of the overall pixel may be recorded by, forexample, a one byte (i.e., 0-255) brightness value. Other data formatsmay be used.

In some embodiments of the device, system and method of the presentinvention, diagnostic data need not be transmitted, but may be sent viaanother method, such as via wire. For example, in an endoscope device,an imaging device at one end may send the data via wire to a receivingdevice.

It may be desirable to limit the amount of time spent transmitting imagedata, and/or the bandwidth required for such a transmission. Embodimentsof the system and method of the present invention may compress image andpossibly other data before transmission. Since compressed data may takeless time to transmit, more data may be transmitted, and more zo framesof image data may be transmitted per time unit, without increasing, foeexample, the bandwidth of the transmitter. Alternatively, the sameamount of data may be transmitted using less bandwidth. Another aspectof the data transmission relates to the transmission systems withlimited energy source. In this case smaller amount of bits needed to betransmitted may enable more energy per bit in the transmission. Dataother than or in addition to image data may be transmitted andcompressed. For example, control information may be compressed.Furthermore, in devices transmitting telemetric information other thanimage information, such as pressure or pH information, such informationmay be compressed. In further embodiments, image data need not betransmitted in discrete portions corresponding to images.

Thus, for example, if the bandwidth of a transmission mechanism permitsan uncompressed frame relay rate of, for example, two frames per secondat a specified bit rate, the same transmission mechanism may be able tosupport the transmission of a greater number of frames per second usingthe same bit rate if the transmitted data is compressed or diluted priorto compression, and then reconstructed after transmission. Thus,according to one embodiment, for areas of the gastro-intestinal tractwhere a greater number of frames per second may be desired (for example,the esophagus, which may be traversed quickly by a capsule), the imagingdevice may operate in a “fast mode” which transmits compressed ordiluted data and may therefore be capable of transmitting a greaternumber of frames per second than uncompressed data. In one embodiment,data may be added by for example interpolation and/or other methods toproduce completed images or images that may be presented as completedimages.

In an exemplary embodiment of the present invention, device 40 includesa data compression module 600 for compressing data transmitted from thedevice 40 and for providing the data to the transmitter 41, possibly viaintermediate circuitry. Data compression module 600 may be implementedas part of a microprocessor or ASIC or other micro-computing device, aspart of the imager 46 or processing chip 47, or in another suitablemanner. In alternate embodiments the functions of the data compressionmodule 600 may be taken up by other structures and may be disposed indifferent parts of the device 40. For example, the transmitter 41 mayinclude data compression capability, or data compression module 600 maybe a stand-alone unit, or may be implemented in software. In oneembodiment, transmitter 41 may include, for example, a modulator 70 forreceiving the video signal from the imager 46, a radio frequency (RF)amplifier 72, and an impedance matcher 74. The modulator may convert theinput image signal having a cutoff frequency of, for example, f_(c) ofless than 5 MHz to an RF signal having a carrier frequency f_(r),typically in the range of 1 GHz (other ranges may be used). While in oneembodiment the signal is an analog video signal, the modulating signalmay be another signal, for example digital rather than analog. Thecarrier frequency may be in other bands, e.g. a 400 MHz band. Themodulated RF signal may have a bandwidth of f_(t). The impedance matchermay match the impedance of the circuit to that of the antenna. Othersuitable transmitters or arrangements of transmitter components may beused, utilizing different signal formats and frequency ranges. Forexample, alternate embodiments may not include a matched antenna or mayinclude a transmitter without a matching circuit. In one embodiment ofsuch an imaging device 40, transmission may occur at a frequency of 434MHz, using Phase Shift Keying (PSK). In alternate embodiments, othertransmission frequencies and methods (such as AM or FM) may be used.

The receiver 12 may preferably detect a signal having the carrierfrequency f_(r) and the bandwidth f_(c) described herein. The receiver12 may be similar to those found in televisions or for example it may beone similar to those described on pages 244-245 of the book BiomedicalTelemetry by R. Stewart McKay and published by John Wiley and Sons,1970. The receiver may be digital or analog. In alternate embodiments,other receivers, responding to other types of signals, may be used.

The receiver 12 preferably includes a data decompression module 610 fordecompressing data received from the device 40. In exemplary embodimentdata decompression module 610 may be a microprocessor or othermicro-computing device and may be part of the receiver 12. In alternateembodiments the functions of the data decompression (decoding) module610 may be taken up by other structures and may be disposed in differentparts or more than one part of the system; for example, datadecompression module 610 may be implemented in software and/or be partof data processor 14. The receiver 12 may receive compressed datawithout decompressing the data and store the compressed data in thereceiver storage unit 16. The data may be later decompressed by, forexample data processor 14.

Preferably, the transmitter 41 may provide overall control of the device40; in alternate embodiments control may be provided by other modules.Preferably, the data compression module 600 may interface with thetransmitter 41 to receive and compress image data; other units mayprovide other data to data compression module 600. In addition, the datacompression module 600 may provide the transmitter 41 with informationsuch as, for example, start or stop time for the transfer of image datafrom the data compression module 600 to the transmitter 41, the lengthor size of each block of such image data, and the rate of frame datatransfer. The interface between the data compression module 600 and thetransmitter 41 may be handled, for example, by the data compressionmodule 600. Typically, the data compression module 600 may compressimage information in discrete portions. Each portion may typicallycorrespond to an image or frame. Other compression methods or sequencesare possible, and other units of compression and transmission arepossible. In one embodiment, to compress the image data, subsequentimages may be compared, and to only differences between these images maybe transmitted rather than each image. Assuming that in most cases thesubsequent images may be similar, the difference between the images maycontain much less information than the image itself.

In alternate embodiments, the data exchanged between the datacompression module 600 and the transmitter 41 may be different, and indifferent forms. For example, size information need not be transferred.Furthermore, in embodiments having alternate arrangements of components,the interface and protocol between the various components may alsodiffer. For example, in an embodiment where a data compressioncapability is included in the transmitter 41 and the imager 46 transfersun-compressed data to the transmitter 41, no start/stop or sizeinformation may be transferred. In another embodiment of the invention,a data compression module 601 may be implemented as part of an imager46′, such as in for example, device 40 shown in FIG. 1B. In oneembodiment of the invention, imager 46′ or another component withindevice 40 may produce a selection of input data to form a diluted image.In such a case, a transmitter 41′ may be a transmitter withoutcompression capability; however, using selections of data andcompression may be performed together. In another embodiment of theinvention, a compression module 602 may be part of a processing chip 47′such as in for example, device 40 shown in FIG. 1C. Processing chip 47and 47′ may be for example, a microprocessor, ASIC, or another suitablemicro-computing device. In yet another embodiment of the invention, acompression module 603 may be included as a stand-alone unit such as infor example, device 40 shown in FIG. 1D.

The data compression module for example, module 600 (or 601, 602 or603), and data decompression module 610, may use various datacompression formats and systems. Compression formats used may includecompression formats where some data may be lost during compression andcompression formats where data may not be lost during compression.Typically, the data compression module 600 and decompression module 610may include circuitry and/or software to perform such data compression.For example, if the data compression module 600 or decompression module610 (or other compression or decompression systems) are implemented as acomputer on a chip or ASIC, data compression module 600 or decompressionmodule 610 may include a processor operating on firmware which includesinstructions for a data compression algorithm. If data decompressionmodule 610 is implemented as part of data processor 14 and/or processor13, the decompression may be implemented as part of a software program.It will be evident to those of skill in the art that compression moduleneed not be a physically separate component, but rather, that itsfunctionality may be performed by another component, such as imager 46′.

The amount of imager data to be sent may be, for example, over 1.35Megabits per second. Compression may reduce this amount. Aftercompression, and before transmission, other operations such asrandomization may occur (performed, for example, by the transmitter 41).For example, the occurrence of the digital signals (“0” and “1”) may berandomized so that transmission may not be impeded by a recurring signalof one type.

FIG. 2 depicts a series of steps of a method according to an embodimentof the present invention. Referring to FIG. 2, in block 200, an in-vivodevice, such as a swallowable capsule, captures image data. Typically,an imager within the device may capture image data of a gastrointestinaltract, but other image data may be captured, for example, image datafrom other body lumens or cavities. Data other than or in addition toimage data may be captured. The image data from the imager may be passedto other units for processing.

In block 210, the image data is compressed. Such compression or otherprocessing may be performed by a processing unit such as, for example,transmitter 41. The image data is typically received from the imager orvia another unit. Such compression may be typically in response to aprocess receiving input data corresponding to an image. In theembodiment shown in FIG. 2, compression may be accomplished by dilutingthe captured data, or by selecting only a pattern of pixels fortransmission. Such creation of a selection of data, where the selectionis typically less data than the original data, may be, for example,performed according to a dilution pattern. Alternately, only thedifferences between for example, pixels or regions of subsequent imagesmay be transferred. The image data may be first loaded or transferredfrom the imager to a compression module, or, alternately oradditionally, may be compressed at the imager. If applicable, data otherthan or in addition to image data may be compressed; in block 215, forexample, sensor data other than image sensor data, control data, etc. Inone embodiment of the invention, for example, data may be selected fortransmission by the imager and then further compressed, for example, byJPEG or another algorithm before transmission. The selected data istypically less data than the original data.

In block 220, the data may be transmitted to a receiver. Typically, thedata, such as for example image data, may be transmitted, for example,using radio waves (RF channel) to a receiver external to the body, butother methods may be used. In alternate embodiments, the image or otherdata may be sent by other methods, such as by wire.

In block 230, the data may be decompressed, enabling reconstruction ofthe image. Reconstruction may include further elements such aspre-processing, post-processing, etc. Reconstructed image data may be,for example, displayed or stored for later use. Alternately, thecompressed image data may be stored for later image reconstruction.

Other suitable steps or series of steps may be used than those describedin the above blocks.

The data compression methods described herein may be lossless or lossy.Lossless data compression may enable precise (with no distortion)decoding of the compressed data. The compression ratio of losslessmethods may however be limited. Lossy compression methods may not enableprecise decoding of the compressed information. However the compressionration of lossy methods may be much higher than of the lossless method.In many cases the data distortion of the lossy methods may benon-significant, and the compress ratio may be high. Without limitationof generality, the description of data compression schemes herein may beapplicable both to lossless and to lossy methods.

In an embodiment of the present invention, compression may beaccomplished by transmitting only portions of the captured imageselected according to, for example, a dilution pattern. While this mayresult in some loss of quality in the resulting image, proper selectionof pixels according to a suitable dilution pattern, together with properreconstruction of the diluted image, may preserve the quality of thetransmitted image and rehabilitate the image to lossless ornear-lossless condition. The dilution pattern may for example bepredetermined, may be selected or created by a component of the devicebased on operating conditions related, for example, to its position inthe gastro-intestinal tract or other surrounding conditions such as pH,temperature, ambient lighting or color conditions, or may be createdusing other methods. Data may be selected for transmission by meansother than a dilution pattern.

Embodiments of the invention are presented herein with differentdilution patterns, although those of skill in the art will recognizethat other dilution patterns may be used for compressed transmission inaccordance with the present invention. In the below exemplary dilutionpatterns presented, there is assumed an imager with 256 rows and 256columns of pixels, each pixel representing one of the colors red, blueor green. The embodiments also show an imager having twice as many greenpixels as red or blue pixels. It will be recognized by those of skill inthe art that the invention may be practiced with imagers of differentconfigurations, sizes, and color patterns. For example, a black andwhite imager may be used.

FIG. 3 depicts one exemplary dilution pattern in accordance withembodiments of the invention that may be used in an imager having, forexample, pixels representing red (R) 302, green (G) 304, and blue (B)306 in the arrangement shown. In this first exemplary dilution patternshown, the imaging device may transmit every, for example, fourth pixelin each row, where, typically, all pixels chosen in any row representthe same color. In the case of three colors, e.g., red, blue and green,one color selected for transmission may repeat every second row, whilethe selection of the other two colors alternates every fourth row. Thus,for example, in the example shown, in two of each four consecutive rows,the color red 308 may be selected, while in the remaining two rows, blue310 and green 312 may alternate every fourth row. Thus, if the array ofpixels in the imager includes 256 rows and 256 columns, the device maytransmit only 64 pixels, or every fourth pixel, for each row.

FIG. 4 depicts another exemplary dilution pattern that may be used inaccordance with embodiments of the invention. In this second exemplarydilution pattern, a pattern may be repeated every four rows, in which nopixels may be transmitted from a first row, every fourth pixel may betransmitted from each of the next two rows, and every second pixel maybe transmitted from the fourth row. In this embodiment, it will berecognized that twice as many green pixels 402 may be transmitted thanred pixels 404 or blue pixels 406.

According to some embodiments of the present invention, the device maytransmit for some or all pixels the difference between the actual valueand a predicted value based on the already determined values of otherpixels, for example, neighboring pixels. The receiver may determine thepredicted value based on the values of the other pixels, and modify thepredicted value by the difference transmitted, thereby reconstructingthe original actual value for the pixel. It will be recognized that thisembodiment of the invention may be implemented as lossless or lossy. Forexample, in one embodiment, for each pixel there may be transmittedeither a value or an exact difference based on a predicted value for thepixel. In such an embodiment, no image quality in the reconstructedimage will be lost. In another example, there may be set a threshold,wherein a difference between the predicted value and the actual valuethat may be less than the threshold may not be transmitted. In thislatter example, some image quality in the reconstructed image may becompromised.

It will be recognized by those of skill in the art that while onlyseveral dilution patterns have been discussed at length, any suitabledilution pattern that selects some pixels or areas for transmissionwhile omitting others may be used in accordance with embodiments of thisinvention. In one embodiment of the invention, producing selected dataincludes for example modifying at least one input datum by reference toat least one other input datum to produce selected data.

Optionally, devices in accordance with embodiments of the invention mayoperate in a “simple” fast mode, an “averaging” fast mode or othersuitable mode corresponding to any suitable dilution pattern, including,for example, the modes discussed herein. In “averaging” mode, the valuetransmitted for a selected pixel of a certain color may be summed oraveraged or otherwise affected by the value of a nearby pixel, typicallya pixel of the same color. For example, in FIG. 3, a pixel 308 selectedby the particular dilution pattern for transmission may be averaged bythe imager with a neighboring pixel of the same color 302 prior totransmission. Averaging may be performed by the compression module, forexample, the imager, or by another component. This “averaging mode” maybe activated or deactivated, for example, by a control bit intrinsic orextrinsic to the compression module, for example, the imager. It will beappreciated by those of skill in the art that any modification of aninput pixel by reference to one or more neighboring pixels, for examplea weighted average, may be used in accordance with the presentinvention.

Also optionally, in an embodiment of the present invention, there may beprovided an error correction mechanism for detecting and correctingerrors. In some embodiments, control or “overhead” information may betransmitted in addition to the pixels of each image, for example,information contained in a prefix header and/or suffix word. Thiscontrol information may or may not be compressed. Various techniques oferror correction are known, any of which may be used in connection withany embodiment of the present invention. In some embodiments of theinvention, the imager may perform error correction encoding.

At the receiver end, various methods may be used in accordance withembodiments of the present invention to reconstruct an image from thediluted data transmitted. The method of reconstruction may vary, forexample, depending on the dilution pattern chosen.

In an embodiment of the invention employing the first exemplary dilutionpattern, a full matrix of color values for each pixel may bereconstructed from the selected pixels using various methods. In someembodiments of the invention, interpolation or weighted interpolationbetween selected data may be used for reconstructing the diluted image.Other suitable methods for reconstructing the data may be used inaddition to interpolation or instead of interpolation. In one embodimentof the invention, edge detection may be used to determine weights forweighted interpolation when reconstructing an image from a dilutedimage. For example, as shown in FIG. 5, the sampled red pixels 502 inthe first dilution pattern may be in a rhomboid pattern. In oneembodiment of the present invention, some or all of the values of fourpixels 602 forming a rhomboid may be used to calculate a value for thepixel at the center of the rhomboid, as depicted by the pixels 604 inFIG. 6. While in one embodiment of the present invention, the fourvalues surrounding a rhomboid center may be averaged, other embodimentsare of course possible. For example, edge detection or other suitablemethods may be used to locate pixels that may be on the edge of anobject. For pixels that may be determined to be on the edge, the centervalue may be determined by for example a weighted average of, forexample, the four surrounding pixels. Whether the pixel may be on anedge may, for example, be determined based on the gradient at thatpixel. Alternately or additionally, the center value may be determinedby a weighted average of a subset of the surrounding pixels. In oneembodiment, the center value may be determined based on the median ofsome or all of the surrounding pixels. In one embodiment, theinterpolation may be on a grid not necessarily in the shape of a square.For example, the orthogonal values between the pixels may be obtained byinterpolation of the four surrounding pixels. Any suitable method may beused for this interpolation, for example, linear, quadratic, bicubic,polynomial, weighted average, or other interpolation. The remainingpixels, which may be located on diagonals between originally selectedpixels, may be interpolated using known methods. Interpolating typicallyhelps to produces additional image data, eventually resulting in areconstructed image.

With respect to the remaining two colors in the first dilution pattern,the missing pixels may be interpolated from the square pattern shown inFIG. 6 by any suitable method of interpolation, for example, linear,quadratic, bicubic, polynomial or other interpolation. The remainingpixels, which may be located on diagonals between originally selectedpixels, may be for example, interpolated using known methods. While onlysome methods of interpolation of missing pixels have been enumerated, itwill be understood by those of skill in the art that any suitable methodof interpolation may be used consistent with any embodiment of thepresent invention.

With respect to reconstructing image data in accordance with the secondexemplary dilution pattern, a similar reconstruction process may be usedas the one described. Thus, for example, the rhomboid pattern created bythe sampled green pixels may be similar to the rhomboid pattern of thered pixels in the first exemplary dilution pattern, and the pixels ofthe remaining two colors are in a square pattern. It will be understoodby those of skill in the art that the present invention is not limitedin the respect of the exemplary dilution patterns (and reconstructionschemes) described above, and that many others may be used in accordancewith the present invention.

In some embodiments of the present invention, there may be furtherenhancement or refinement of the reconstructed image. In someembodiments of the present invention, the resulting image may besmoothed by modifying the color values of the originally selectedpixels, for example, by replacing the original value by a weightedaverage of the original value taken together with some or all values ofthe surrounding selected pixels, for example, a median value of thesurrounding pixels.

The various compression and/or dilution methods discussed herein neednot be used with a device having more than one mode, or a “fast mode”,but may be utilized for various other purposes. Further, compression anddilution of pixels need not be used together.

Typically, a compression and/or dilution process is carried out bycontrol circuitry in the device 40, such as transmitter 41. Similarly,reconstruction and/or decompression may be carried out by for example,data processor 14, decompression module 610, processor 13, etc., or bystructures in the receiver 12. Of course, in other embodiments, suchprocesses may be carried out by other components, and of course themethods discussed herein may be carried out in devices having structuresother than that of devices 40, receiver 12, and data processor 14. Forexample, control processes such as producing the selection of input datamay be carried out by an imaging component, or another component. Forexample, a portion of a controller may be considered to be within theimaging unit.

Furthermore, in some embodiments of the present invention, enhancementmay be made by for example modifying the intensity values of the imageto restore them to near the original values. For example, the intensityof a reconstructed pixel may be calculated using only or predominantlythe values of nearby originally selected pixels. In another embodiment,intensity for each pixel may be obtained by using the values of pixelsof only one color, for example, green. It will be recognized that othermethods of obtaining intensity values for reconstructed pixels may beused consistent with embodiments of this invention.

In some embodiments of the present invention, there may be lessening ofcolor artifacts due to the process of dilution and reconstruction of theimage, for example, by suppressing colors of pixels located on edgesfound in the image. In some embodiments of the invention, colorsuppression may also be used to correct color-saturated pixels during,for example, reconstruction.

In some embodiments of the present invention, a pre-processing block maybe added for the original samples. For example, in one embodiment, agradient evaluation for enhancing edges may be added. Additionally, inone embodiment of the invention, a post-processing block may be addedfor enhancing reconstruction, for example, for correcting interpolationartifacts, for example, periodic artifacts. In one embodiment, theseartifacts may be corrected in the frequency domain by convolution ormedian filter.

FIG. 7 depicts a series of steps of a method for reconstructing adiluted image or other suitable data according to an embodiment of thepresent invention. Referring to FIG. 7, in block 700, selected data, forexample a diluted image data, may be received. For example, the data maybe received at a receiver 12, a data processor 14, or other suitablestructure. In block 710 pre-processing may be performed on data orselected data. Pre-processing may include for example, clearing errorswith error correction code, reducing noise, performing a gradientevaluation for detecting and enhancing edges, calculating intensity,etc. Other suitable pre-processing may be used. In step 730,interpolation may be performed to, for example, fill in gaps betweendata. Interpolation may include, for example, linear, quadratic,bicubic, polynomial, weighted average, or other suitable interpolation.Edge information may be used to weight differently each of the samples.For example, pixels along directions with high gradient (possibly closeto an edge) may, for example, not be included in interpolation. Othersuitable weighting factors may be included. In one embodiment of theinvention, intensity may be calculated and used during interpolation formaintaining the ratio between color and intensity during interpolation.Other suitable interpolation methods may be implemented. Afterinterpolation, post-processing may be performed on interpolated data inblock 760 to, for example enhance reconstructed image. Post-processingfor enhancing a reconstructed image may include, for example imagesharpening, color suppression, intensity adjustment, convolution or amedian filter. Other suitable post-processing techniques may beimplemented.

Embodiments of the present invention may include apparatuses forperforming the operations herein. Such apparatuses may be speciallyconstructed for the desired purposes (e.g., a “computer on a chip” or anASIC), or may include general purpose computers selectively activated orreconfigured by a computer program stored in the computers. Suchcomputer programs may be stored in a computer readable storage medium,such as, but is not limited to, any type of disk including floppy disks,optical disks, CD-ROMs, magnetic-optical disks, read-only memories(ROMs), random access memories (RAMs), electrically programmableread-only memories (EPROMs), electrically erasable and programmable readonly memories (EEPROMs), magnetic or optical cards, or any other type ofmedia suitable for storing electronic instructions.

The processes presented herein are not inherently related to anyparticular computer or other apparatus. Various general purpose systemsmay be used with programs in accordance with the teachings herein, or itmay prove convenient to construct a more specialized apparatus toperform the desired method. The desired structure for a variety of thesesystems appears from the description herein. In addition, embodiments ofthe present invention are not described with reference to any particularprogramming language. It will be appreciated that a variety ofprogramming languages may be used to implement the teachings of theinvention as described herein.

Unless specifically stated otherwise, as apparent from the discussionsherein, it is appreciated that throughout the specification discussionsutilizing terms such as “processing”, “computing”, “calculating”,“determining”, or the like, typically refer to the action and/orprocesses of a computer or computing system, or similar electroniccomputing device (e.g., a “computer on a chip” or ASIC), that manipulateand/or transform data represented as physical, such as electronic,quantities within the computing system's registers and/or memories intoother data similarly represented as physical quantities within thecomputing system's memories, registers or other such informationstorage, transmission or display devices.

While the invention has been described with respect to a limited numberof embodiments, it will be appreciated that many variations,modifications and other applications of the invention may be made.Embodiments of the present invention may include other apparatuses forperforming the operations herein. Such apparatuses may integrate theelements discussed, or may comprise alternative components to carry outthe same purpose. It will be appreciated by persons skilled in the artthat the appended claims are intended to cover all such modificationsand changes as fall within the true spirit of the invention.

1. An in vivo device comprising: an imager for capturing in vivo imagedata, the imager comprising rows of pixels; a controller to receive thein vivo image data, and to dilute the image data using a dilutionpattern, wherein said dilution pattern is repeated in every four rows ofthe captured image data, such that every second green pixel is selectedfrom a first row, every second blue pixel is selected from a second row,and every second red pixel is selected from a third row; and atransmitter to transmit diluted image data.
 2. The device of claim 1wherein the dilution pattern used to dilute the image data is modifiedbased on operating conditions of the device.
 3. The device of claim 2wherein the operating conditions are selected from a group consisting ofposition of the in vivo device, pH, temperature, ambient lighting orcolor conditions.
 4. The device of claim 1 wherein the dilution patternfurther comprises selecting a same amount of red pixels and blue pixelsand twice that amount of green pixels.
 5. The device of claim 1 whereinthe dilution pattern further comprises selecting every second greenpixel from said second row, and selecting no pixels from a fourth row.6. The device of claim 1 wherein the dilution pattern further comprisesselecting every second red pixel from a fourth row, such that a sameamount of green pixels and blue pixels are selected and twice thatamount of red pixels are selected.
 7. A system for dilution of in vivoimage data for subsequent reconstruction thereof, the system comprisinga data compression module to: receive image data acquired by an in-vivoimager, the imager comprising rows of pixels; and dilute said image datausing a dilution pattern, wherein said dilution pattern is repeated inevery four rows of the image data, such that every second green pixel isselected from a first row, every second blue pixel is selected from asecond row, and every second red pixel is selected from a third row. 8.The system of claim 7 wherein said data compression module isimplemented as part of a transmitter in an in vivo device.
 9. The systemof claim 8 further comprising a receiver to receive the diluted imagedata.
 10. The system of claim 7 wherein said dilution pattern furthercomprises selecting a same amount of red pixels and blue pixels andtwice that amount of green pixels.
 11. The system of claim 7 whereinsaid dilution pattern further comprises selecting every second greenpixel from said second row, and selecting no pixels from a fourth row.12. The system of claim 7 wherein said dilution pattern furthercomprises selecting every second red pixel from a fourth row, such thata same amount of green pixels and blue pixels are selected and twicethat amount of red pixels are selected.
 13. A method for dilution of invivo image data comprising: capturing in vivo image data by an in vivoimager, the data arranged in rows of pixels; diluting the captured imagedata according to a dilution pattern, wherein the dilution patternwherein the dilution pattern is repeated in every four rows of the imagedata, such that every second green pixel is selected from a first row,every second blue pixel is selected from a second row, and every secondred pixel is selected from a third row; and transmitting the dilutedimage data to a receiver.
 14. The method of claim 13 wherein saiddilution pattern further comprises selecting every second red pixel froma fourth row, such that a same amount of green pixels and blue pixelsare selected and twice that amount of red pixels are selected.
 15. Themethod of claim 13 comprising reconstructing an image from the dilutedimage data.
 16. The method of claim 13 wherein the dilution pattern ispredetermined.
 17. The method of claim 13 wherein the dilution patternis created by a component of an in vivo device comprising the imager,based on operating conditions selected from: the position of the devicein the gastro-intestinal tract, pH, temperature surrounding the device,ambient lighting or color.
 18. The method of claim 13 wherein thedilution pattern further comprises averaging the value of a selectedpixel of a certain color with the value of a nearby pixel of the samecolor.
 19. The method of claim 13 wherein the averaging is activated ordeactivated by a control bit.
 20. The method of claim 13 wherein the invivo imaging device is a swallowable capsule.